Hinduism, Confucianism, Judaism, Druidism, and general Paganism are just a few examples.
Christianity
No, no they did not. They had their own religion which predates the bible. They weren't christians and had their own beliefs on things.
Hades is not a figure in Christian religion. In Greek mythology, Hades was the god of the underworld, while in Christian belief, the concept of hell is associated with punishment after death for those who have sinned. Hades and hell represent different beliefs and traditions.
they studied Christianity after they were conquered
The dominant religion in the Roman Empire was the Roman religion until Christianity became the dominant religion.
No, the Phoenix predates Christianity
Before Christianity came to Britain, the priests of the ancient Briton were of the Druid religion. This was a pagan religion and they offered human sacrifice.
Before Christianity, they were pagan.
No, cuneiform predates it by a few thousand years. Cuneiform was used in ancient Babylon, which had a polytheistic religion.
Over 5000 years ago and predates Christianity.
Yes ancient Greece and ancient Egypt have gods and goddesses. They also have modern religion of Islam and Christianity.
Christianity thanks to all the misionary work it is over 50%